IMHO it would be nicer to either add this alongside the cube and allow switching between the two (with a possible name change for the plugin) or to use the patch as-is but change the name of the plugin (not much of a cube anymore).

That's an easy change to make - you just need to add a key binding that changes which shape data structure you point to and reinitialize. I didn't do it for brevity. Agree it's more likely to get the patch included that way. Then again, if someone wants to add that keybinding, it makes sense to add a bunch more shape data (linuxstb suggested adding all of the convex polyhedra, which is doable given that non-triangular faces can be rendered automatically now).